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Full text of "First Annual Shenandoah Research Symposium--April 1976"

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Shenandoah 



National Park 



First Annual Shenandoah Research Symposium 

April 1976 




National Park Service 
U. S. Department of the Interior 



FEDERAL 
PUBLiCAliON 



Digitized by the Internet Archive 

in 2012 with funding from 

LYRASIS Members and Sloan Foundation 



http://archive.org/details/firstannualshenaOOnati 



Shenandoah 



National Park 



First Annual Shenandoah Research Symposium 

April 1976 



National Park Service 
Mid-Atlantic Region 
143 South Third Street 
Philadelphia, PA 19106 



Natural Resources Reports Number 11 



PREFACE 



This volume includes papers presented at the First Annual 
Shenandoah Research Symposium held at Shenandoah National 
Park, April 9-10, 1976. The papers cover such topics as 
plant sucession on abandoned homesites; vegetation responses 
to management burning at Big Meadows, Shenandoah National 
Park; a spring burn's impact upon vertebrates at Big Meadows; 
a consideration of black bear populations in Virginia; and 
the Shenandoah salamander. 

Some of the papers report on research projects conducted 
in cooperation with Shenandoah National Park but at no 
park expense. The National Park Service strongly endorses 
such mutually beneficial research whereby the Service 
acquires professional studies about its parks, and researchers 
are afforded opportunities to utilize park resources . 

Superintendent Robert R. Jacobsen initiated the symposium 
because of his enthusiasm for cooperative research at 
Shenandoah National Park. He intends to continue welcoming 
such scholarly study there and values the associations it 
produces with colleges and universities. He would be 
delighted to respond to inquiries about possible future 
research, which should be addressed to: 

Superintendent Robert R. Jacobsen 
Shenandoah National Park 
Luray, Virginia 22835 

We wholeheartedly support Mr. Jacobsen' s interest in 
cooperative research and believe that his symposium 
was one of the Region's outstanding activities in 1976. 



Benjamin J. Zerbey 
Acting Regional Director 
Mid-Atlantic Region 



li 



CONTENTS 



Vegetation Responses to Controlled Burning 

at Big Meadows, Shenandoah National Park 1 

W. Dean Cocking, Assistant Professor of 
Biology, Madison College 

Effects of a Spring Burn Upon the Vertebrate 

Community at Big Meadows, Shenandoah National Park. . 4 
Peter Dalby, Assistant Professor of Biology, 
University of Virginia 

Plant Succession on Old Homesites 12 

Elwood Fisher, Associate Professor of Biology, 
Madison College 

The Endemic Salamander, Plethodon shenandoah , 

of Shenandoah National Park 15 

Richard Highton, Professor of Zoology, 
University of Maryland 

History of Botanical Research in Shenandoah 

National Park 18 

Peter M. Mazzeo, U.S. National Arboretum 

Study of Black Bear Populations in Virginia 28 

Jack W. Raybourne , Game Research Biologist, 
Virginia Commission of Game and Inland 
Fisheries 

Status of Knowledge of the Geology of Shenandoah 

National Park 38 

John C. Reed, Jr., Chief, Office of 
Environmental Geology, U.S. Geological Survey 

Monitoring Forest Insect Outbreaks in the Shenandoah. .47 
Timothy C. Tigner, Entomologist, Insect and 
Disease Investigation, Virginia Division of 
Forestry 



in 



VEGETATION RESPONSES TO CONTROLLED 
BURNING AT BIG MEADOWS 

W. Dean Cocking" 



The fire ecology project at Big Meadows in the central 
section of Shenandoah National Park is a cooperative effort 
involving local park service personnel, scientists from 
several educational institutions and Dr. Robert Stottlemyer 
from the Mid-Atlantic Regional Office of the National Park 
Service. The experimental prescribed burns carried out in 
the Spring of 1975 for the purposes of our study were the 
result of efforts by Ray Schaffner, Robert Jacobsen, 
Clark Baker, and many others. This paper will describe 
some of the preliminary results of our participation in 
the project. The majority of the field work was carried 
out by Steve Lilly and Emily Baxter, graduate students 
in the Department of Biology at Madison College. We have 
been looking at the growth rates and community composition 
of the regenerating meadow vegetation and hope that the 
resultant data, combined with the soil and faunal observa- 
tions of Dr. Norman Chris tensen and Dr. Peter Dalby, will 
give a complete picture of the ecosystem response to pre- 
scribed burning . 

Big Meadows is at an intermediate stage of secondary succes- 
sion and is therefore similar to the majority of the 
communities within Shenandoah National Park. The progress 
of succession at this site, however, has been periodically 
set back by fall mowing, the frequency of which has increased 
during the last decade until it is now virtually an annual 
occurrence. The purpose of this management practice has 
been to maintain open space adjacent to the Byrd Visitor 
Center and has resulted in a mosaic of herbaceous "grass- 
land" and shrub "briar" communities . The increasing size 
of black locust stems over the last decade has made the 
mowing practice more difficult, and this project is designed 

-Assistant Professor of Biology, Madison College, 
Harrisonburg, Virginia 



to look at the feasibility of using fire to maintain the 
earlier stages of succession. Without some form of manage- 
ment, the meadowland will disappear and young successional 
forest will take its place. 



The present mowing technique has two major disadvantages. 
First, it is an increasingly expensive and time consuming 
endeavor. Second, it appears to be stabilizing the community 
as a shrubland of Rub us spp . (blackberries and dewberries) 
and Robinia (black locust) . Should this happen, the herbacious 
species will disappear from the region due to their inability 
to compete successfully. Information from this study will be 
helpful in making management decisions concerning whether 
mowing, burning or a combination of both will be appropriate 
in the future . 

Sixteen small plots (approximately % acre each) were 
selected within the dry, upland part of Big Meadows. One 
half were in the "grassland" community type and the rest 
in the "shrub-briar" community. Within each community type 
two plots were mowed as usual in the fall of 1974, two 
were burned on April 15, 1975, two received both treatments, 
and two received neither treatment and served as experimental 
controls . 

Detailed discussion of the data from this study will be 
presented later, along with the results of a much more 
extensive spring burning carried out last week. However, 
it is possible to discuss some of our observations at this 
time. One of the primary investigations concerned the immediate 
effects of the burn on the physical environment. Temperatures 
during the burn were approximately 300 to 350 °C, a rela- 
tively warm fire, but not extremely hot in comparison 
with temperatures attained in some forest fires. We examined 
soil temperatures five days after the burn and found slight 
increases in the blackened areas as a result of the 
greater absorption of light by the dark soil surface. 
The impact of this warmth on spring growth remains to be 
established. Dr. Christianson has analyzed soil samples 
taken two months following the burn and reports increases 
in potassium, calcium, magnesium, nitrogen and other ions. 
This greater nutrient mobility may promote better growth 
during the subsequent summer, however, this also remains to 
be determined. Another question which interested us was 
the rate of recovery from burn to green meadowland. Regrowth 
was extremely rapid in all burned plots, and very little 
evidence of the fire remained by mid-summer. 

Quantitative assessment of the burn impact was carried 
out in two ways. We sampled the tissue by physically 



collecting the above ground vegetation, drying it in an 
oven, and determining the dry weight of living and dead 
components of various species groups . We also used a 
sampling frame to determine the amount of soil surface area 
covered by the individual species . Recovery in "grassland" 
at the end of the growing season in August was more complete 
than that of the "shrubland." However, both community types 
were very repairable following the prescribed burns . 

We are also interested in changes in species composition 
of the communities which might result from the use of 
burning as a management practice. Initial examination of the 
data indicates that some species, e.g., the Fragaria , Solidago , 
Achillea , Potentilla and Rubus, increase in relative 
cover while others, such as Dennstaedtia , Polytrichum , 
Lycopodium and Robinia , decrease following the burn 
treatment. The dynamics of these species composition changes 
will hopefully become more evident following the present 
study . 

In conclusion, we feel assured from the initial project that 
burning and mowing are similar in their effect on the com- 
munity and that the use of fire to set back succession will 
not result in prolonged damage to the ecosystem. We are not 
presently in a position to predict the effect on individual 
species. However, we do know that species present in the 
meadow are dependent on the open conditions of herbaceous 
and shrub communities and will certainly disappear if the 
community completes the successional process and returns to 
forest . 



EFFECTS OF A SPRING BURN UPON 
THE VERTEBRATE COMMUNITY AT BIG MEADOWS, 
SHENANDOAH NATIONAL PARK 

Peter L. Dalby* 



I hope to make this presentation a bit broader in coverage 
and possibly a bit more philosophical in nature than just 
examining the effects of a spring burn upon the vertebrate 
community at Big Meadows. Since plants and animals are 
difficult to separate completely from each other because of 
their interrelationships, you will note some overlap with 
the report given by the plant ecologist on this project, 
Dr. Cocking. 

Before progressing further, I would like to acknowledge the 
support of the National Park Service, Tall Timbers Research, 
Inc., an organization dedicated to fire ecology research, 
and of course, the Shenandoah Natural History Association. 
A past V.P.I. & S.U. graduate student, John Niess, also 
contributed to the earlier portions of this study. The 
field work was completed while the author was associated 
with V.P.I. & S.U. 

Superficially, and from a non-ecologist ' s viewpoint, one 
might accept the argument that the use of fire is warranted 
simply to determine if it is an effective and economical 
tool for maintaining cleared areas. Overlooks, old home- 
stead sites, and others such as Big Meadows fall into this 
category. Does mowing, brushing, or bush-hogging such sites 
create more, the same, or less damage than a controlled 
burn? Which technique, the time-honored method or burning, 
is most successful in reducing unwanted species for the 
longest period of time? Above all, what is the cost-benefit 
ratio built into the time-honored methods versus controlled 
burning? 

^Assistant Professor of Biology, University of Virginia, 
Charlottesville, Virginia 



As interesting as the above questions are, studying the 
effects of controlled burning in Big Meadows has progressed 
further than simply attempting to reduce the ubiquitous 
black locusts ( Robinia pseudoacacia ) and briars (blackberries, 
Rubus sp.). An attempt is being made to monitor the kind 
and the intensity of change due to fire, both to the plant 
and the animal community. In other words, more than a 
casual examination is being given to the locusts and briars, 
two of the major early succession woody plants invading Big 
Meadows and other open areas in the park. Less dominant 
and less conspicuous species are also being qualitatively 
and quantitatively sampled. It is important to document not 
only how the fire directly affects the animal life, but also 
how the change in vegetation affects the local fauna. 

There is an amazing dearth of information concerning the 
effect of fire upon the flora and fauna of the eastern 
United States. This is in sharp contrast to the respectable 
data bank accumulated for the western and also for the 
southeastern United States. Most of this information was 
gathered by those interested in forest management or forest 
recovery; much less is known of the effects of fire upon 
grasslands, particularly as it pertains to the eastern 
United States . 

There are several reasons why Big Meadows was chosen for 
the burn project over other areas within Shenandoah National 
Park. First, Big Meadows is the largest (125-150 acres) 
high altitude (3500 ft. or 1067 m.) grassland meadow in the 
park. Therefore, it allows a great deal of flexibility 
concerning experimental design, especially as it pertains 
to plot size and number. Second, it is logistically ideal 
because it is reasonably centralized in respect to the 
institutions involved in the study and it is near a road 
and housing/ camping facilities. Third, the importance of 
Big Meadows, both in the past and the present, serves as an 
additional rationale for efforts to preserve its exceptional 
qualities without further delay. 

There is some evidence that the Indians maintained the field 
condition of the Big Meadows area through the use of fire. 
Strawberries, blackberries, and blueberries were abundant 
during various portions of the summer; probably other 
"crops" were gathered also. In addition, the meadow 
certainly attracted bison, elk, white-tailed deer, several 
species of rabbits and hares, woodcock, and probably other 
game species. 

Presently, Big Meadows is a focal point in the park's 
camping and naturalist programs. Birding, watching for 



deer and other mammals , identifying flowers , and general 
hiking activities are only a few features which make Big 
Meadows so popular. As the forest tends increasingly to 
dominate the park scene, clearings such as Big Meadows 
present an alternate vista of openness to the park visitor. 
More importantly, Big Meadows and other open areas in the 
park serve as a refuge for a number of plant and animal 
species partially or solely dependent upon a grassland 
community for their existence. 

Methodology 

Because of the plot sizes agreed upon by all those involved 
in the project (see Dr. Cocking' s presentation for a 
description of the plots) , it was decided for at least the 
first year to concentrate mainly on sampling the invertebrate 
soil and litter fauna. This is for very obvious reasons. 
They are plentiful, and there are good sampling techniques 
so statistical analysis of the data is reasonably easy. We 
hope to examine the small mammal (rodents and shrews) and 
bird communities, however, the plots are rather small for 
this kind of work. Although the data that can be gathered 
may be meager, it still provides a ballpark estimate of what 
happens as a result of controlled burining. 

The collection of invertebrates was done during ten sampling 
periods, at three week intervals, starting in April and 
finishing at the end of October. By using a stratified 
random design, four soil and litter samples were taken from 
each 25 m. square plot. The sampling was taken with a 10% 
inch (25 cm.) diameter metal band, about 5 inches (12% cm.) 
in width. With the band encircling the sampling area, a 
shovel cut the sod along the inner perimeter of the band. 
Then the 1-2 inches (2.5-5.0 cm.) thick plug of sod was 
pried loose, placed into a plastic refuse bag, and sealed. 

At the university, usually half of the samples were placed 
in a cooler (5°C) and the remainder processed immediately. 
A Berlese funnel system was constructed in order to extract 
the invertebrates. A cloth cover over the funnel prevented 
escape from the top. A lamp over each funnel provided 
enough heat to drive the invertebrates out of the soil and 
into a jar (containing a solution of 907 o ethyl alcohol) 
attached to the funnel. After a week the sod was discarded 
and the jars containing the results were capped and stored 
until the material could be identified. The remainder of 
the samples which had been under refrigeration were then 
placed on the funnels. Approximately 500 samples were 
collected and processed. 



The small mammal community in the study plots was monitored 
by using an approximately equal number of small (54 x 64 x 
171 mm.) and large (75 x 75 x 227 mm.) Sherman live traps. 
Nine traps were placed in each 25 m. square plot, following 
a grid pattern in which the traps were set at about 8 m. 
intervals. Rolled oats was used as bait, and the traps were 
set at dusk and checked the following morning. This procedure 
was followed for two consecutive nights. Trapping occurred 
at the beginning of the study, just prior to burning, again 
during the middle of the summer, and lastly in October at the 
termination of the study. A total of 648 trap-nights (one 
trap set for one night equals one trap-night) were accumulated. 

The birds were periodically watched during the season, 
particularly by Mr. Niess, who was employed as a summer 
naturalist at the Big Meadows Visitor's Center. Most of the 
observations were taken during the beginning of the study when 
home territories and feeding areas became established. The 
results of this portion of the study are of a qualitative 
nature. When the opportunity arose, observations on other 
animal species were also taken. 

Preliminary Results 

The Burlese funnel invertebrate material remains to be 
identified and I have no preconceptions about changes that 
might have occurred during the study. However, we were able 
to make some observations. Of considerable importance to 
the pollinating insects was their use of the unburned and 
unmowed briar patches as a food base during the spring blos- 
soming period. One of the interesting facts concerning 
briars is that they are biennial plants, and, once mowed or 
burned back to ground level, any recovery during that growing 
season is entirely vegetative. Flowering occurs only on 
second year and older cane. With the annual mowing and bush- 
hogging which has occurred for the last 30 or so years on Big 
Meadows , pollinating insects have certainly had one food 
resource literally cut out from under them. Annual use of 
fire will have the same effect. Although the smaller blue- 
berry bushes could escape the mowing operation, the others 
were trimmed to the point where they too did not flower to 
any appreciable degree until the second year. Fire had the 
same effect; in fact fire might be a bit more severe in the 
sense that fewer stems escape damage. As a result, the 
pollinating insects had two plant types eliminated from their 
food resources. Certainly later in the year these same plants, 
if allowed to flower, would have provided a substantial amount 
of fruit for many fruit-eating species of insects, birds, 
and mammals . 



As for small mammals, essentially nothing was found. In the 
spring one adult short-tailed shrew ( Blarina brevicauda ) , was 
found dead during an invertebrate sampling period. It may 
have been killed by a fox and discarded because of their 
apparent ill taste. One subadult meadow vole ( Microtus 
pennsylvanicus ) was captured during the last trapping period 
of the season. Such a paucity of small mammal life in Big 
Meadows has existed for quite some time as evidenced by 
trapping records for the last 5-10 years on file at park 
headquarters. I would speculate that part of the reason 
might be due to the large biomass of nonvascular plants 
(mainly mosses) found on the study sites. Over the years, 
mowing has probably favored that type of growth over the 
grasses and sedges. I suspect that by the proper use of fire, 
one can increase the amount of sedge and grass cover. In fact, 
Dr. Cocking 's report tends to verify this. With a larger 
biomass of sedges and grasses there might be an increase in 
the number of meadow voles . This in turn could tend to 
increase the number of owls , hawks , skunks , and foxes , all of 
which prey to some extent on this species. In other parts of 
Big Meadows, for instance, in some of the lower and higher 
areas away from the study sites, there are limited patches of 
dense grass cover inhabited by meadow voles, as discerned by 
observation of their runways. These mice can serve as nuclei 
for future invasion into other parts of Big Meadows. 

There are only about a half dozen woodchuck ( Marmota monax ) 
holes near or within the study sites, but one quickly notices 
that these are almost exclusively found in the briar thickets , 
although the animals ' feeding usually takes them out of this 
cover. If an attempt is made to eliminate all the briars 
from Big Meadows, it is certain to have a dire effect upon 
the woodchuck population. From much walking in Big Meadows 
I would estimate that there are 50-100 active woodchuck dens, 
nearly all associated with the briar and to a lesser degree 
the locust (1-3 m. in height) stands. The preference of some 
low woody growth around potential den sites is well documented 
for woodchucks and its elimination or reduction will decrease 
the woodchuck population. This might not be entirely 
undesirable except it must also be kept in mind that rabbits, 
skunks, and other species, including some amphibians and 
reptiles, also utilize the same holes. 

The information on birds is mostly qualitative in nature. 
There are several generalizations which can be made, however, 
concerning the effects of the burn upon them. 

1. Fire does not seem to have an immediate negative 
effect on birds. In fact, several species which 
appear to prefer feeding areas with short cover, 

8 



such as robins ( Turdus migrator ius ) , vesper 
sparrows ( Poocetes gramineus ) , grackles ( Quiscal us 
quiscula ) , and starlings ( Sturnus vulgaris ) seemed 
to be more frequent in burned than in unburned 
areas. This activity continued until the new 
growth was well established by mid-summer. The 
loss of leaf litter and possibly the warming of 
the soil made the bird prey more visible and 
probably more active because of the warmer soil 
temperatures. It is obviously difficult to 
determine whether a bird has a behavioral prefer- 
ence for a particular habitat or is at a site 
because of food availability. 

2. Vesper sparrows, song sparrows ( Melospiza melodia) , 
field sparrows ( Spizella pusilla j^ indigo buntings 
( Passerina cyanea ) , bluebirds ( Sialia sialis ) and 
possibly a few others selected the burned, but 
still standing dead cane of the briars, and the 
standing, but dead locusts, as perching sites. This 
observation was not discernible until several weeks 
into the study when unburned briar and locust sites 
were well leafed. It seemed to hold true under 
several different circumstances: a bird would 
alight to "rest," to sing a territorial song, or 

to perch between periods of foraging activity on 
the ground. Obviously such perching sites gave 
the bird a clear field of vision. 

3. Two known species, namely the song sparrow and the 
towhee ( Pipilo erythrophtohalmus ) nested in the 
standing unburned, unmowed , 1-3 m. tall locusts. 
While both species are common in the area, mowing 
or burning every 2-3 years instead of every year 
would insure added nesting sites for these two 
species, among others. 

4. Burning or mowing is necessary to maintain an 
open courtship area for woodcock ( Philohela minor ) . 
Very preliminary results suggest that courting males 
in burned sites remain in such sites. During a 
good spring evening there is no doubt, after 
listening to the large number of woodcock 
utilizing Big Meadows, that it is an important 
breeding ground. 

Data on a number, probably a majority, of the species men- 
tioned above are less than conclusive. However, the picture 
described, albeit crudely drawn, can still be recognized as 
a picture. Certainly the finer lines have to be added. 



Other characters , such as skunks , opposums , and deer are 
still missing from the drawing. The herps (reptiles and 
amphibians) pose a special problem. There is a small 
population of wood frogs (Rana sylvatica ) , spring peepers 
( Hyla crucif er ) , and American toads ( Bufo americanus ) that 
breeds in the several small ponds situated in Big Meadows. 
The ponds often dry up before the tadpoles undergo meta- 
morphosis so it is a marginal breeding site at best. Yet 
the number of other potential breeding sites in the immediate 
vicinity is unknown. Probably burning will not harm their 
breeding activities, but still they should be monitored. 

The reptiles are represented by box turtles ( Terrepene 
Carolina ) , green snakes ( Opheodrys vernalis ) , ring-necked 
snakes ( Diadophis punctatus ) , and garter snakes ( Thamnophis 
sirtalis ) . The green snakes and garter snakes are typical 
field snakes and, as a result, are rather unique to Big 
Meadows. The effect of burning on their welfare is unknown. 
In fact, at this point there are more "unknowns" than 
"knowns" concerning all the above species and the effect of 
fire on their existence. Yet, based on what is known a 
few concluding remarks can be made. 

Concluding Remarks 

Big Meadows owes much of its uniqueness to its great 
diversity of plants; the diversity of animals found at Big 
Meadows is partly dependent on this plant diversity. The 
complex, mosaic distribution of plants and animals within 
the meadow allows for the following: 

1. Certain animal species are dependent upon 
essentially a single plant species habitat. For 
example, if you have a pure species stand of 
briars , then very likely there are going to be a 
certain invertebrate and vertebrate species that 
will, for all practical purposes, lead their 
entire life (or life cycle) within that briar 
patch. 

2. Many species are ecotonal in nature. That is, 
some species may nest in one habitat yet move to 
another to forage. These species are dependent 
upon two or more habitat types in close proximity 
for their livelihood. 

3. As open meadows continue to shrink every year in 
the park because of forest encroachment, there 
eventually comes a time when there is not enough 
room in the meadow to sustain viable populations 

10 



of either of the above two types. In effect, 
animals inhabiting the area are now woodland 
forms, the meadow forms having been extirpated. 

It is the complexity, the mosaic pattern of life in Big 
Meadows which aids in making the area the plant and wildlife 
showplace that it is. There is a need to keep the complexity 
in order to maintain the richness, yet at the same time 
there must be a pureness in order to insure the survival of 
other species which contribute to the area's richness. Is 
mowing or fire the best management technique to use in order 
to sustain or even increase Big Meadows' richness? Which- 
ever method is eventually utilized, burning or mowing in 
swaths is highly recommended, following a 2-3 year 
rotational program. This by itself will be an improvement 
over the practice of mowing the whole field every year. 
Burning or mowing should be done as early (burning) or as 
late (mowing) as possible in order to minimize damage to 
the animal (and plant) community. Burning or mowing should 
be thought of as successful management tools only if they 
can control in a more or less steady-state condition the 
complex of plant and animal life presently found on Big 
Meadows. In other words, the spread of briars and locusts 
is to be controlled; there is no desire nor ecologically 
sound rationale to eliminate either from Big Meadows . 
Finally, fire has been documented to play a very important 
natural role in some ecosystems. It may be that fire once 
played an important ecological role in this part of the 
country also. Fire has always been a double-edged sword 
for man. It is up to us at Shenandoah National Park to learn 
how best to use the tool that Mother Nature has been using 
for eons . 



11 



PLANT SUCCESSION ON FORMER HOMESITES 
Elwood Fisher* 



The need for this study occurred to me while I was directing 
a Master of Science thesis for Paul R. Lee, a Shenandoah 
National Park naturalist, on "A Study of the Impact of the 
Exotics Lonicera japonica and Alanthus altissima on the 
Shenandoah National Park Ecosystem." I felt that results from 
such an investigation would be currently useful to the interpre- 
tive staff of the park, as well as to academicians of the 
future . 

The park is really a very unique laboratory for ecologists. 
It is an experimental plot of immense proportions where 
cultivation and other forms of land use had completely changed 
the natural environment in almost every section. This region, 
occupied by some 350 families, was almost instantly allowed 
to start its return to primeval conditions , providing 
scientists with a rare opportunity to study roles and patterns 
of plant succession in this ecosystem. 

For the sake of clarity many plant ecologists draw rather 
fixed, over-simplified models of plant succession. Due to 
the number of variable habitats and factors of an area as 
large as the park, these models do not hold true when investi- 
gated under actual field conditions. In fact, succession 
is a mosaic of a variety of sere-types, often in areas of close 
proximity. The soil type, degree of mineral exhaustion, amount 
of erosion, exposure to sun and wind, slope, type of natural 
cover, local animals, fires, "mother seed trees,'' frost 
pockets, elevation, and related factors are foremost in deter- 
mining the rates and patterns of succession. 

Peter M. Mazzeo (1966) catalogued the species of exotics 
at the Skyland site. His study and the one by Paul Lee (1973) 
are the only published attempts at accessing the succession 
in any part of the park prior to my studies of former 

^Associate Professor of Biology, Madison College, Harrisonburg, 
Virginia 

12 



homesites. Basically I am trying to record the exotics 
that have survived, and to determine the degree of their 
adaptability in the midst of encroachment by the endemics. 
I am also trying to interpret the order and rate at which 
the endemics advanced into the homesite and surrounding 
fields. I am using increment borings to determine the age 
of the dominant trees on the site, when in question or if 
relevant. 1 make a plant list for each site, noting the 
incidence of dominant, co-dominant, common, and sparse species, 
both exotic and endemic. 

For the most part, the techniques I have employed are the 
observational methods of a naturalist. I grew up in a similar 
environment during the depression years and can interpret 
and relate to the mountain farm and life-style. I used the 
1927 through 1937 series of United States Geological Survey 
fifteen minute quadrangles in locating the sites. Though 
many of the old trails are no longer visible I can generally 
take a compass sighting from the spring to the homesite 
and find the house foundation readily. All homesites had a 
nearby spring, a prerequisite to life in the mountains. 

I intend to visit each site during two seasons, spring and 
autumn. In the spring I look for flowering bulbs and other 
spring flowering plants. Late summer and autumn data catalogues 
plants not seen in the vernal season. At this time I have data 
for at least one of the two seasons for ninety percent of 
the sites in the Southern Section of the park. I have some 
data for the sites in the Central Section, but very little 
for those in the Northern Section. 

The Lonicera j aponica (Japanese vine honeysuckle) is always 
present on homesites at lower elevations. The Alanthus 
altissima (tree of heaven) , Vinca minor (common periwinkle 
or graveyard myrtle) , Syringa vulgaris (common lilac) , and 
Hemerocallis fulva (day lily or beauty of the day) are the 
four exotic species of ornamentals most frequently found 
at all elevations, The various species of Rosa are also 
numerous , but it is very difficult to differentiate 
between the many varieties and species . Of the exotic 
herbs, the Taraxacum officinale (common dandelion) and Arctium 
minus and A~ lappa (common and great burdock) appear to 
be most common. 

Of the endemic plants , it appears that Pinus virginiana 
(Virginia pine) , Prunus serotina (black cherry) , Sassafras 
species, Robinia pseudo-acacia (black locust), and Crataegus 
species (hawthorn) are the most agressive pioneer species of 
the formerly cultivated areas in the park. The soil qualities 
such as dryness and fertility, among other factors, determine 

13 



which of these species dominates the earliest sere. On a 
few sites I have found species other than the above which 
first colonized the vacated land, but rarely is this the case. 

In addition to cataloguing the exotic and endemic plants 
I have kept a sharp eye for artifacts on or near each site. 
These items, along with the size and workmanship of the 
foundation of the former house, gives me some idea of the 
life-style and occupation of the former residents. I also 
record bird species and other animals seen at each site. Since 
the type of sere is still changing, this information may 
be useful to later investigators. 

Hopefully I shall complete the study of the Southern Section 
of the park and have a manuscript prepared by 1978. 



14 



THE ENDEMIC SALAMANDER, PLETHODON SHENANDOAH, 
OF SHENANDOAH NATIONAL PARK 

Richard Highton* 



Mr. Raybourne's paper on the black bear reviews the interest- 
ing work being done on the largest vertebrate in Shenandoah 
National Park. I want to talk about some of the research we 
have been doing on the two smallest terrestrial vertebrate 
animals living in the park. 

The first is the Shenandoah Salamander, Plethodon s henandoah 
Adults of this species are only three to four inches long. 
As far as we know, this salamander is found nowhere else 
in the world, although it has close relatives in the Cheat 
Mountains of West Virginia and in the Peaks of Otter area of 
the Blue Ridge of Virginia. Not only is the Shenandoah Sala- 
mander restricted to the park, but it is apparently confined 
to northwest facing talus slopes of only three of the park's 
highest mountains, Hawksbill, Stony Man, and the Pinnacle. 
On all three of these mountains the entire distribution of 
the Shenandoah Salamander is in each case no more than three- 
quarters of a mile in diameter. 

The Shenandoah Salamander occurs in two color phases , or 
morphs , which are merely genetic color pattern variations 
of a single species: the unstriped or dark color morph 
and the striped color morph characterized by a narrow red, 
reddish yellow, or yellow dorsal stripe. The two morphs 
occur in approximately equal frequencies on Hawksbill 
Mountain, but the striped morph is much more abundant than 
the unstriped morph on Stony Man Mountain, and we have found 
only the striped morph on The Pinnacle. 

The red-backed salamander, Plethodon cinereus , is probably 
the commonest terrestrial vertebrate over much of its range 
in northeastern United States and southeastern Canada. It 

*Prof essor of Zoology, University of Maryland, College 
Park, Maryland 

15 



is a close relative of the Shenandoah Salamander and is very- 
similar in appearance, occuring in both striped and un- 
striped color phases , but is usually somewhat smaller and 
more slender than shenandoah . Striped cinereu s have a wider 
dorsal stripe than striped shenandoah , and the stripe is 
more often red than yellow. The body of Shenandoah National 
cinereus is slightly more elongated than that of shenandoah 
with an average of twenty trunk vertebrae as opposed to 
nineteen in shenandoah . There is more dorsal brassy-colored 
flecking on the back of unstriped cinereus than on unstriped 
shenandoah , and the belly of shenandoah is much darker than 
that of c inereus because the white mottling is greatly 
reduced. 

Although the red-backed salamander occurs in virtually all 
the wooded areas, it apparently is usually absent from the 
dry open talus slope areas where there is little soil and 
evaporation rates are extremely high. This includes the 
major part of the talus slopes on Hawksbill and Stony Man 
Mountains, but suprisingly we have found cinereus throughout 
most of the talus slope on The Pinnacle Mountain where 
conditions are perhaps different from those in most of the 
park' s slopes . 

Most of our field work in the park was done in 1965 and 1966 
soon after we discovered shenandoah . It was officially 
described and given a scientific name in 1967. During that 
period two graduate students, Richard D. Worthington and 
Robert G. Jaeger, and 1 did extensive field work on the 
distribution of the two species in the park. We failed to 
find shenandoah on any of the other high nearby mountains , 
even those with northwest facing rocky talus slopes. 

The closest relatives of shenandoa h are nettingi , which 
inhabits the spruce forests in the Cheat Mountains of West 
Virginia, and hubricht i , an inhabitant of the high deciduous 
forests of the Peaks oF Otter region of Virginia. The distri- 
bution of the three forms is one we regard as relictual; the 
three presently isolated populations are now very restricted 
in their distributions but at one time probably had a much 
more widely distributed common ancestor. At first we thought 
that shenandoah might have subsequently become adapted 
to living only in rocky talus habitats , but the brilliant 
work of Robert G. Jaeger on the ecology of shenandoah and 
cinereus has clarified the reasons for their present ecologi- 
cal distributions, at least on Hawksbill Mountain. I am sorry 
he was not able to attend this meeting to tell you about his 
work himself. 

In a series of experiments on the moisture requirements of 
shenandoah and cinereus , Dr. Jaeger found that both species 

16 



have similar moisture and substrate preferences: both prefer 
soil to rock under dry conditions but do not differ in the 
substrate preference in wet conditions. Probably partly 
because of its larger size, s henandoah is better able to 
withstand desiccation than cinereus . Thus shenandoah is not 
confined to the talus slopes because it is adapted only to 
this habitat; indeed it would probably do better in surrounding 
woodlands now occupied by cinereus . It is surviving only in 
a suboptimal habitat that is periodically too dry for cinereus 
to live in. 

Dr. Jaeger did additional experiments in enclosures set up 
in the field in both talus and woodland habitats. Ten individ- 
uals of cinereus were placed in cages in the talus and in 
the soil outside the talus. All of the cinereus in the soil 
survived for 12 weeks , but none in the cage in the dry talus 
survived that long. A similar comparison of shenandoah 
resulted in moderate survival in the dry talus and complete 
survival in the soil habitat. When 10 individuals of both 
species were placed in a single cage, one in each habitat, 
shenandoah had a higher rate of survival in the talus , but 
cinereus had a much higher rate of survival in the soil out- 
side the talus. Since shenandoah did very well in the soil 
without the presence of cinereus , Dr. Jaeger concluded that 
cinereus was competitively superior to shenandoah in the 
soil outside the talus. There is considerable evidence to 
indicate that food may be the limiting resource for which 
the two species are competing. Immediately after a rain, these 
salamanders emerge from their burrows and find food in the 
form of small insects and other forest floor inhabiting in- 
vertebrates to be very abundant. Because of their susepti- 
bility to desiccation, these animals are not able to come out 
to feed on dry nights , so food may be regularly in short 
supply. It is interesting that the largest shenandoah , being 
so much bigger than adult cinereus , are able to survive in 
the woods outside the talus by eating larger food items than 
cinereus can consume, but presumably their young are not 
able to compete successfully with cinereus and are never 
found more than a few feet from the talus habitat. 

It would appear, then, that shenandoah is a formerly wide- 
spread species that has been displaced by a more modern and 
efficient competitor. It survives only in a suboptimal 
habitat that is periodically too dry for cinereus because 
of its better ability to withstand desiccation. But the future 
is probably bleak for shenandoah because as the talus errodes 
more and more soil is produced and cinereus is at present 
entering into these pockets of moist soil and will presumably 
displace shenandoah and eventually cause its extinction. 



17 



HISTORY OF BOTANICAL RESEARCH IN 
SHENANDOAH NATIONAL PARK 

Peter M. Mazzeo* 



It is always a pleasure to return home, as it were, to 
Shenandoah National Park. I had the distinct pleasure of 
working here for three seasons, while a student in college 
and shortly thereafter. So it's nice to be home again and 
especially here at Skyland, the heart of Shenandoah National 
Park. 

When I first came to the park area in 1962, I was interested 
in the vegetation of the area. No one before that time had 
done a serious study, except for the various checklists and 
supplements that had been prepared. So I began a rather 
intensive study of the vascular vegetation in the park, and 
tried to supplement what was already known. My remarks are 
based primarily on a history of the botanical collecting 
undertaken before that time and an up-date based on subse- 
quent research. 

Although Shenandoah National Park will be only forty years 
old on July third, the eve of our nation's Bicentennial, most 
of the botanical study that has been done in this area dates 
back to around the turn of the twentieth century. Very little 
is known about the botany of the area before that time. There 
is one indication going back to the very early 1800 's which 
is somewhat interesting and perhaps explains in part 
the reason for the apparent lack of interest in the botany 
of these mountainous areas, namely, lack of accessibility 
to the park area. Benjamin Smith Barton, a Philadelphia 
physician and botanist, and a good friend of Thomas Jefferson, 
was making a survey trip down through the Great Valley of 
Virginia and parts of West Virginia. In his journal dated 
August 26, 1802, Mr. Barton wrote the following: "Between four 
and five o'clock in the afternoon, I left Hays and passed 



*U.S. National Arboretum 

18 



through the gap in the mountains called Rock Fish Gap. I 
observed nothing very remarkable on the way. On the mountain, 
I observed some of the same kind of red earth so common 
in the area in which I had just left, [referring to the 
Triassic soils of the piedmont plateau area] . Near the 
summit of the mountain, there is a tavern. But I thought it 
proper to proceed on my journey. I readily discerned that 
the descent on the western or rather nothwestern side of the 
mountain is much less considerable than the ascent on the 
east or southeast side [of the mountain]." As time went on, 
roads were built through the area, but, for whatever reason, 
botanical studies were not made until the present century. 

The first apparent collections of any consequence date to 
1901, and were made by Edward S. Steele and his wife, who were 
visitors to Stony Man Camp here at Skyland. The early Stony 
Man Camp was one of the main drawing cards to the Blue Ridge 
Mountains, one of the first beloved areas, as it were. It 
is interesting to note that of all the taxonomy collected, 
that is, all the various species that were collected and 
documented with herbarium specimens by Steele in 1901 from 
the vicinity of Stony Man Mountain, all but one have been 
relocated today in basically the same area. A notable 
exception is the bearberry, Arctostaphylauva-ursi , which is 
not only rare in this part of the country but has not been 
seen, to the best of my knowledge, since 1901 when it 
was collected at an altitude of 3600 feet on Stony Man 
Mountain. I know that Mr. Stevens has been looking for it, 
and hopefully this plant may be rediscovered in the park. 

Two other botanists, William Palmer and W.H. King, both of 
the Smithsonian Institution in Washington, made collections 
in the period of 1901, 2, 3, 4, 5, and thereabouts. The next 
major collections that we encounter in the park were made 
by Iver Tidestrom, a botanist with the U.S.D.A. in Washington. 
Many of his collections date back to 1912, 1913-14, again 
primarily in the vicinity of Stony Man Mountain. 

In the nineteen twenties Edgar T. Wherry, at that time a 
geologist with U.S.D.A., made extensive collections in the 
Blue Ridge Mountains. Dr. Wherry is probably more familiar 
to many of us for his work with phlox. He is the author of 
a monograph on the genus Phlox that today is the standard 
reference work for that plant group. Most of his collections 
are located in herbaria either in Washington or Philadelphia, 
where he later became a professor at the University of 
Pennsylvania. Dr. Wherry was also very helpful to me when I 
was preparing my book on the ferns of Shenandoah National Park 

P.L. Ricker, the president of the Wildf lower Preservation 
Society in Washington, made extensive collections in the 

19 



Blue Ridge Mountains in the '20s and for many years there- 
after. He was very instrumental in locating some of the 
rather unusual plants found growing in the vicinity. There 
are other botanists from the Washington area, others from 
Baltimore and Philadelphia, who made collections to document 
the flora of the park at that time. 

The main intensive collecting period began in the 1930' s, 
primarily in conjunction with the establishment of the National 
Park in this part of the eastern United States. We find many 
notable botanists collecting at that time, including F. Raymond 
Fosberg and Egbert H. Walker, both botanists in the Washington 
area. They made intensive field studies, documented the flora 
with herbarium specimens, and catalogued over eight hundred 
species which they published in the first major listing of 
vascular flora of the park area, entitled the "Preliminary 
Check List of Plants of the Shenandoah National Park," in 
1941. The very first publication dealing with the flora of 
the park, however, was published in 1935. This was not about 
the vascular plants but rather the fungi found growing in the 
area. It was published by John Stevenson, a curator in the 
National Fungus Collections of the U.S.D.A. in Beltsville, 
Maryland. 

During this period, W.H. Camp of the New York Botanical Garden, 
who was especially interested in the Ericaceae , the Heath 
family, made numerous collections in the area. He identified 
many hybrid forms growing in the park. As many of you probably 
know, it is not always easy to identify distinct species 
of the park's blueberries because of the hybrid forms found 
there . 

E.H. Fulling, also of the New York Botanical Garden, did 
extensive collecting in the area during the mid-1930's. In 
1936, he published a paper on a new variety of Balsam fir 
named Abies intermedia , the Blue Ridge Fir. It is rather 
unusual to find this particular variety so far south in the 
Blue Ridge Mountains , or the Southern Appalachian Mountains , 
but here it is on Stony Man Mountain, the Crescent Rocks 
area, and Hawksbill. A few years earlier, M.L. Fernald of 
Harvard University had described a very similar plant from 
New England, and later Abies intermedia was reclassified 
and grouped in with Abies balsamea variety phanerolepsis . 

Dr. Ruskin Freer, a professor of botany at Lynchburg College, 
made extensive collections in the area of southern Shenandoah 
National Park between Rockfish Gap and the Roanoke area. On 
various occasions he would come up and meet with botanists 
collecting in what is now the park. His work has been instru- 
mental in furnishing a history of botanical collections and 
research in the park. 

20 



Arther H. Leeds and Frances Harper, both of Philadelphia, 
also made many collections important to the documentation of 
the park's flora. J.E. Benedict, Jr., a seed tester from the 
Washington area, made valuable collections. I understand 
his private herbarium was recently acquired by V.P.I, and 
S.U. at Blacksburg. 

All of the various plant species that had been collected and 
documented with herbarium specimens to prove the existence 
of these various taxa from the park area, were catalogued 
and published in 1941 in the "Preliminary Check List of 
Plants" by Fosberg and Walker. 

The National Park was established and dedicated in 1936: 

the Skyline Drive and Appalachian Trail system were constructed, 

providing access to the "backbone" of the Blue Ridge Mountains. 

Accordingly, many more botanists became interested in the 

area. 

During the early 1940 's an Englishman by the name of E.K. 
Balls, who was in the Washington area with the War Department, 
made extensive collections, primarily on Old Rag Mountain. 
This was the first major botanical "expedition" to the Old 
Rag area. Mr. Balls produced several new records for the 
park flora. 

H.A. Allard, another U.S.D.A. botanist from Washington, was 
interested in the flora of the northern part of Virginia 
and made extensive studies in the Bull Run Mountain area, 
as well as the Blue Ridge and various other places in 
northern Virginia and northern West Virginia. O.M. Freeman 
of the U.S.D.A. also collected quite a bit in the Blue Ridge 
Mountains. Dr. F. Ewan of Tulane University made various 
collections near the Washington area. E. Graff, Assistant 
Secretary of the Smithsonian Institution, collected in 
the park. Fred J. Hermann, perhaps the most knowledgeable 
botanist on the genus Carex , the sedges, made and identified 
numerous collections. E.P. Killip of the Smithsonian Institu- 
tion and Warren H. Wagner, Jr. , at that time a graduate 
student, but now a professor at the University of Michigan, 
collected in the Blue Ridge Mountains. (Dr. Wagner is 
most notably known for his work on the ferns .) Frances W. 
Hunnewell of Wellesley, Massachusetts, also made many collec- 
tions in the Blue Ridge Mountains , including some in 
Shenandoah National Park. 

There is a very good story to mention at this time. If you 
browse through Gray's Manual of Botany , you will see listed 
in there Diervilla sessilifolia , which is a species commonly 
found in the southern Appalachian Mountains. When Mr. 
Hunnewell made a collection from Warren County, Virginia, 

21 



along the Skyline Drive, it was cited in the eighth edition 
of Gray's Manual of Botany as being a rather disjunct 
population. Fortunately , he had made a herbarium specimen. 
Some botanist later questioned the validity of that disjunct 
record from Warren County, and when the specimen was scruti- 
nized by other botanists it was decided that the plant was 
not really Diervilla sessilifolia , but rather Diervilla 
lomicera , a species that is common in the Shenandoah National 
Park and other mountain regions of eastern North America. 
This is a good illustration of the importance of specimens 
for documentation of botanical research. 

Fosberg and Walker published the first supplement to their 
"Preliminary Check List" in 1943. Meantime, members of the 
park staff began studying the area's vegetation: W.D. Chick, 
a park naturalist, a park forester named Moore, and Griffing, 
the landscape architect. Unfortunately many of their plant 
catalogs were not documented with herbarium specimens but 
only were named in the park Check List. Now we are not sure 
if some of those taxa are correctly represented in the park 
or not. In 1948 Fosberg and Walker published a second 
supplement to the Check List. 

One notable plant that had been discovered in the southern 
section of the park was Xerophyllum asphodeloides , the turkey 
beard, a member of the Lily family. It s a rather unusual 
plant, common in the New Jersey Pine Barrens, found here on 
some of the mountains in the southern section of the park. 
It is rather curious that this plant should be in that area. 
I've been there to look for it myself a couple of times and 
have never yet seen it in flower. I've seen the plant growing 
there with a persisting inflorescence, the flower cluster and 
stalk from a previous year. The plant apparently blossoms 
every other year, so hopefully I'll get a chance to see 
it in flower and will collect it when I do. 

In 1945, the first major paper and Check List on the Bryophytes 
of the park was published by Irma Schnooberger and Frances 
E. Wayne, both from the University of Michigan. This is 
the only such paper on this section of the plant kingdom. 

Botanists continued to collect in the area during the 1950 's, 
and, in 1955, a third supplement to Fosberg and Walker's 
"Check List" appeared. In 1959, Fosberg published a fourth 
paper entitled "Notes on the Park Flora." 

The first major publication involving a group of vascular 
flowering plants in the park was published in 1958 by Grant 
and Winona Sharpe entitled 101 Wildflowers of Shenandoah 
National Park , a very handy small guide book to the more 
common wildflowers in the area. Unfortunately this book is 

22 



now out of print. This book was one in a series the authors 
have prepared for various national parks such as Shenandoah, 
Mt . Ranier, and other national parks in the western part of 
the country. The Sharpes are associated with the University 
of Washington in Seattle. 

During the 1960's, more and more people became interested in 
the flora of the park and we find for the first time a 
major interest developing among amateur botanists. Many 
people, with permission, collected specimens or took photo- 
graphs that provided or documented park records . These include 
Virginia Phelps, of Pittsburgh; Henry Heatwole, a park 
collaborator, who is with us today; Hugh Crandall; Charles E. 
Stevens of Charlottesville, Virginia, also with us today; 
and many seasonal park employees - there are several, so 
unfortunately I won't cite each one by name. Their contri- 
butions have been significant, particularly in documenting 
more remote areas of the park, and their records have 
provided valuable supplements to the check list of the park 
flora. 

In the 1960's, other publications about the plant life in the 
park became available. Most notably, in 1965 Arthur Stupka 
published his Wildf lowers in Color , a "tri-Park" book. It 
is a superb publication with very good kodachrome reproductions 
of the wildf lowers growing in Shenandoah National Park, the 
Blue Ridge Parkway and the Great Smoky Mountains National 
Park. For the first time we had a comprehensive or much larger 
publication dealing with the wildf lowers , perhaps the vege- 
tation most attractive to many of the park visitors. 

In 1965 Fosberg and I published yet another supplement to 
the park's Check List, adding to the record a more detailed 
study than had yet been done of genera such as the genus 
Tilia , the basswoods, a rather complex genus found growing 
naturally throughout most of eastern North America. As 
many as four different taxa or species had been described 
for this genus in the park. However, a recent monograph 
helps to explain some of the floristic problems. We now 
think there's actually just one species growing in the 
park area [which means I must update Trees of Shenandoah 
National Park ] . The genus Crataegus , hawthorns , also has 
been given some attention, but it remains a problem group 
despite our best efforts. 

When I joined the staff of the Shenandoah National Park I 
continued my collections there. A period at the National 
Arboretum in Washington engendered an interest in cultivated 
plants, or plants persisting from cultivation, in areas like 
the park. Many of these I had documented during the years 
I worked here as a ranger-naturalist. In 1966, I published 

23 



a small paper on many of the ornamentals , both woody 
and non-woody, found growing or persisting at old homesites 
in the park area. One superb place to locate exotic 
ornamentals is near the old Judd property at Skyland. There 
are more exotics persisting there than any place else in 
the park. 

In 1967, I published another supplement to the "Check List" 
of park plants, and in 1968, I published a book dealing with 
the identification of the trees of Shenandoah National Park. 
Subsequently, more species have been identified and I think 
the book is ready for updating. 

A further supplement to the Check List was published in 1972. 
The total known number of species in the park was then just 
under 1200. We have actually catalogued 1195 taxa used to 
include species, sub-species, etc. for the park area. In 
1972, I also published or prepared the book on ferns and the 
fern allies of the park as proposed by the Natural History Assoc- 
ciation. This was the first major treatment given to that 
interesting group of vascular plants. 

What is going to happen in the future? Hopefully botanists, 
both professional and amateur, will continue to study in 
the park and to document and publish their findings. I 
feel strongly that one's knowledge of the flora is critical 
to any other research involving the park vegetation. Mr. 
Stephens is going to publish another supplement to the 
Check List, setting many new records. This will be in print 
in the next year or so. Dr. Fosberg, who unfortunately could 
not be here today, has for some years now been trying to 
correlate the original Check List and all of the supplements 
into one document, annotated with habitat data. I have been 
working on a supplemental list myself with assistance from 
Mr. Peterson, an amateur botanist from the Washington area 
who has spent hours in the park each year looking for some 
rather unusual plants and trying to fully document each of 
the park taxa. Individuals like Dr. Fisher are doing their 
research on some of the various species found specifically 
at old homesitas in the area. 

There are undoubtedly other people who have been collecting, 
f loristically speaking, data from the park area, many of 
whom are unknown to me. But hopefully through meetings such 
as this we can exchange ideas and information which increase 
our awareness of the park vegetation. Some day we might have 
a complete list of these plants , if indeed it is possible to 
do such a project in view of the fact that there are always 
some plants moving in or moving out of the area. Some botan- 
ists say they like to study plants and collect plants 
because they don't move around like insects. Some species 

24 



do migrate; they don't have limbs or legs, but they 

certainly do migrate into and out of areas , and for this 

reason the flora of the park will probably never be 100% 
completely known. 



25 



A SELECTED BIBLIOGRAPHY OF BOTANICAL LITERATURE 
ON SHENANDOAH NATIONAL PARK, VIRGINIA 



Fosberg, F.R. Notes on the Shenandoah National Park Flora. 
(Fourth Supp.). Castanea 24: 135-143. 1959. 

Fosberg, F.R. and E.H. Walker. A Preliminary Check List 

of the Plants in the Shenandoah National Park, Virginia 
Castanea 6: 89-136. 1941. 

First Supplement to a Preliminary Check List of 



Plants in the Shenandoah National Park, Virginia 
Castanea 8: 109-115. 1943. 

_. Second Supplement to a Preliminary Check List 
of Plants in the Shenandoah National Park, Virginia. 
Castanea 13: 83-92. 1948. 

Third Supplement to a Preliminary Check List of 



Plants in the Shenandoah National Park, Virginia 
Castanea 20: 61-70. 1955. 

Fosberg, F.R. and P.M. Mazzeo. Further Notes on Shenandoah 
National Park Plants. (Fifth Supp.). Castanea 30: 191- 
205. 1965. 

Mazzeo, P.M. New Additions to the Shenandoah National Park 
Flora. (Sixth Supp.). Castanea 31: 236-240. 1966. 

. Native and Exotic Ornamentals in the Shenandoah 

National Park. Amer. Hort. Mag. 45: 419-421. 1966. 

New Additions and Notes to the Shenandoah National 



Park Flora. (Seventh Supp.). Castanea 32: 177-183. 1967. 

_. Notes on the Conifers of the Shenandoah National 
Park. Castanea 31: 240-247. 1966. 

_. Trees of Shenandoah National Park in the Blue 
Ridge Mountains of Virginia. 80 pp. , Illus. , Shenandoah 
Natural History Association, Bull. No. 3, Luray , 
Virginia. 1968. 

_. Further Notes on the Flora of The Shenandoah National 
Park, Virginia. (Eighth Supp.). Castanea 37: 168-178. 
1972. 



26 



. Ferns and Fern Allies of Shenandoah National Park. 

52 pp., Illus., Shenandoah Natural History Association, 
Bull. No. 6, Luray, Virginia. 1972. 

Schnooberger , Irma and F.E. Wayne. The Bryophytes of 

Shenandoah National Park, Virginia. Bull. Torrey 
Club 72: 506-520. 1945. 

Sharpe , G. and W. 101 Wildf lowers of Shenandoah National 

Park. 1-40 pp., Illus., Univ. of Wash. Press, Seattle. 
1958. 

Stevenson, J. A. A Preliminary List of the Fungi of Shenan- 
doah National Park. Claytonia 3: 21-28. 1936; 3: 31- 
35. 1937. 

Stupka, A. Wildf lowers in Color. XIV plus 144 pp., Illus., 
Harper and Row, New York. 1965. 



27 



BLACK BEARS 



Jack W. Raybourne* 



I'd like to brief you, if I may, a little bit on the work 
we're conducting in Virginia on the black bear. It's an 
animal that is quite controversial, to say the least. It's 
an animal also that is very, very difficult to get much 
good information on. Our aim in the study is to establish 
biological bases on which to manage Virginia's bear 
population. There are different avenues of enjoyment for 
different individuals and we're going to try to come up 
with some ideas that will help not only the hunting public 
that I work for but also the visitor who enjoys seeing 
these animals, as all of us do. 

Our study of the black bear is state-wide in scope and includes 
lands here on the Shenandoah National Park where we find 
about 25%, roughly, of the state-wide black bear population 
as we currently know it. Other prime study areas are the 
United States Forest Serivce lands, Virginia Game Commission 
lands and selected private lands in the Commonwealth. The 
Shenandoah National Park serves as the primary control area, 
if you will, for the studies that we are doing. It is the 
largest single block of "non-hunted" land that we have availa- 
ble in the state. It gives us a good "control" from the stand- 
point that it shows us what we should expect in terms of 
population phenomena: births, deaths, and movements which 
should occur in a non-hunted area. We do know that this 
area is illegally hunted, regardless of how we might want 
to think of it. The periphery, of course, can be legally 
hunted, It's a large area; manpower is limited and certain 
types of individuals will take advantage of the situation. 
Still, it serves as the best available control area for 
our study. 

We are trying to establish an age and sex structure on the 
bear population similar to what a life insurance company 

*Game Research Biologist, Virginia Commission of Game and 
Inland Fisheries 



28 



does with humans. From this we can predict, based on the 
production rates , and the mortality factors (not only 
hunting but accidental causes of death, disease, and what 
have you) that occur in a population. Reproductive factors 
are highly important in black bears since they are so 
unusual in their biology. They are "induced ovulators" and 
"delayed implanters." The former "fifty-cent words" meaning 
they shed their ova during the physical act of mating, 
as do rabbits. They are also delayed implanters like the 
weasel and mink family. The fertilized ovum implants at some 
later point in the gestation period. In the case of bear, 
which normally breed June-August, the fertilized ovum 
divided into two, then four, eight, sixteen cells to a 
bias tula stage. It then free floats in the uterus until about 
mid-December at which time light conditions are such that it 
implants into the. wall of the uterus and begins a very rapid 
development. The young are born in late January or early 
February. The black bear has both of two conditions that are 
very unusual in the animal kingdom. In addition they only 
breed every other year and don't reach normal maturity until 
three years of age. 

We have two studies in progress designed to improve our 
overall knowledge of this fine animal. I think about the 
best way to show you what we're doing is by way of photographs, 
I'll describe a bit of the work we're doing, what we 
hope to accomplish and some of what we've found out to date. 
We have one more year ahead of us of actual trapping, tagging- 
type work. The primary thing that we're after is a small 
premolar tooth with which we can establish a bear's age. 

The Game Commission, National Park Service, and the U.S. 
Forest Service have collaborated in this study of the black 
bear. The problems associated with such an investigation, 
though great, have fortunately now been overcome to a large 
extent. The first problem primarily concerned terrain. 
Bears live in typically remote, inaccessible, very rugged 
terrain that creates problems for researchers in getting 
equipment into the study area. Additionally, because of their 
low production potential, bears simply do not provide as 
great numbers of animals to study as do deer, turkeys, 
squirrels, etc. Compounding these two problems has been a 
means of handling bears in a manner safe to the operator and 
the animal itself. We now have tools available to us that 
will allow us to do this. 

There is a Southeastern Association of Game and Fish Commis- 
sioners which some of you may be familiar with. I am a 
member of the Black Bear Sub-Committee under this organization 
which is coordinating various research studies designed to 
maximize several phases of bear research simultaneously. 

29 



We have divided the "puzzle" so that each researcher is 
working on a separate "piece" of the unknown. It is planned 
that this knowledge be pooled so we can put the puzzle 
together as quickly as possible. Each state or set of states 
has a different problem such as reproduction, home range, 
habitat, determination of age and sex structures, etc. 
We're trying to gain as much as we can as quickly as we can 
on this animal now that we have the tools available. 

Bears can do a considerable amount of damage. They are a 
very powerful animal. There's nothing quite like coming back 
and finding a convertible, with the top destroyed, "easy 
pickings" for a bear, in which someone has left food items. 
This becomes a real problem for the park and also for the 
visitor who is unfortunate enough to have left something in 
his Car which is attractive to a bear. 

I want to point out that of the many bears we've trapped 
in this park, only about 10% have been known to frequent 
campgrounds at all. The other 907 o are free-roaming, free-ranging 
wild black bears that stay in back country areas. Fortunately, 
the Shenandoah has not had, to my knowledge, the "panhandling 
bear" evident in the Great Smoky Mountain National Park. 

Bears cause some crop and property damage to adjacent land 
owners. This occurs primarily to corn from July to September 
when corn is in the tender milk stage. The natural fruits and 
berries are gone and, at this point, nuts, acorns, etc. 
have not yet fallen. Fresh corn is attractive, to say the 
least. It wouldn't be so bad if the bears' activities were 
confined to eating, but they destroy a lot while fighting, 
wrestling, etc., especially the young males. We've observed 
bears literally riding down a row of corn, allowing those big 
stalks to run across the chest. It evidently fells good! 
We caught fourteen bears in one farmer's corn field in a 
week's time. They can destroy a tenth of an acre in one 
night. If a farmer has a corn patch in a small open field 
that's rocky, mediocre farm land to begin with, it's all 
he's got; and if it's right next to "Bear Heaven," he's 
got a problem! Fortunately we've been able to take care of 
many of these landowner complaints. We trap and relocate 
problem animals to a new habitat in western areas of the 
state with the hope of "rehabilitating" them. A percentage of 
them do return. 

Black bears are such creatures of habit that instead of 
making evenly-depressed trails they form little pads or 
depressions that are rather obvious in heavily-used bear 
country. Where you don't have deer in the area you can see 
this fairly readily. Each bear travelling the trail steps 
in the footprints of its predecessor until obvious depressions 

30 



result. This habit is a "natural" for using a new type of 
trap known as the Aldrich Foot Snare. Previously, when 
anyone mentioned bear traps the listener thought of powerful 
steel traps that were extrememly dangerous. The Aldrich 
Foot Snare is a very safe, humane trap. A small child can 
step into one of these and get out of it just by simply 
loosening the noose. It will hold the animal in place until 
we get there with a dart gun. We simply dig up one of the 
depressions on a bear trail and set the snare noose, made 
of 42 inch aircraft cable with 4,200 pounds of tensile 
strength. We also can use baited sets with this type trap. 
The simplest baited set consists of two small anchor trees, 
four to six inches in diameter, about two feet apart. Then 
we build a closed "horseshoe" out of small saplings about 
four feet deep, with the two small trees serving as the mouth 
of the horseshoe. The set is then baited. They'll come around 
the open end. Black bears have very soft, sensitive pads 
on the bottoms of their feet. They won't step on anything 
sharp, such as a stone or a stick, that they can avoid. By 
strategically placing stepping stones and sticks, we can 
direct his feet into the area of the snare trigger. 

The culvert trap is used exclusively in the Shenandoah 
National Park since there is less danger to the public 
when the bear is in this type of trap. They are marked 
very clearly so that anyone knows that it is a bear trap. 
The culvert trap is potentially more dangerous to people 
than the snare, particularly if small children were to be 
playing around it. The door weighs about 50 pounds. We visit 
these traps daily. They weigh approximately 500 pounds 
empty. With a device that heavy, plus a bear that may weigh 
as much, handling of traps was formerly a problem. To solve 
this we strengthened the truck's tail gate, attached a cargo 
roller track, and added an electric boat winch. The winch 
has been absolutely indispensable to us. We use it for all 
loading of traps and weighing of animals. 

The new drug which we have available to us now is known 

as M-99 Etorphine. It's a synthetic morphine compound and is 

extremely powerful and has an antagonist that works with it. 

It generally takes effect in 15 minutes, making the animal 

"high as a kite." The animal's respiration rate drops 

dramatically, but the heart rate remains esentially stable, 

about one beat per second. We don't attempt to handle the 

animals now until the respiration rate drops to about 

one inspiration per twenty seconds. Normally they pant very 

quickly, like a dog. 

There are two different kinds of injecting devices, one 
for liquids and one for solids. The drugs currently in 
use come in liquid form. The drug formerly used was known 

31 



as Sucostrin (Succinylcholine Chloride) . It is a skeletal 
muscle immobilizer which was pre-assembled in disposable darts 
with excellent shelf-life in the dry form. It can be kept 
almost indefinitely, pre-loaded. Unfortunately, in the case 
of an accidental human injection or bear overdose there is 
no antagonist for Sucostrin except oxygen. With the dosage 
required to immobilize a black bear, accidental injection 
would probably mean certain death for a human. 

To my knowledge, the drug that we are now using has not 
been tested on humans. Injection is done at point blank 
range with a CO2 dart pistol. Within 15 minutes, normally, 
the bear is sufficiently anesthetized to handle. The first 
thing we do is to weigh each animal and affix a numbered metal 
tag in each ear. Each tag has a reward inscription to en- 
courage individuals to report any dead bears to our agency. 
This gives us an opportunity to monitor bear mortality 
and survival on a sample basis by sex, age, time of year, 
etc. Tag data also provides information on weight gain and 
movements . 

We collect a variety of measurements on these animals once 
we've got them in hand. Some information collected is not 
needed presently, but is collected with the possiblity of 
future use. Various head measurements are taken along with 
total body length, shoulder height, heart girth and measure- 
ment of the front and rear pads. There appears to be a degree 
of correlation between heart girth and weight by sex. 

Gerald Blank is a trapping specialist with our agency. 
He's been instrumental in developing a lot of the techniques 
that we utilize not only on black bears but for live trapping 
other species as well. 

We take an extra step to permanently identify individual 
bears in addition to ear tagging. Some studies in other 
states have indicated that one or both ear tags may be lost 
the first year, particularly by the males, due to fighting, 
greater movement, etc. We tattoo the lowest ear tag number 
inside the upper lip as a permanent means of identification 

The primary thing that we're after is an age and sex structure 
on the population. Establishing an accurate age has been the 
biggest problem that has beset black bear researchers. Turkey, 
deer, and many other species can be aged very accurately. 
Age and sex data along with reproduction data has allowed 
us to manage deer populations to numbers far greater than 
the Pilgrims found when they came to this country. Current 
statewide deer harvests exceed 66,000 animals due largely 
to planned management on a sustained-yield basis. We've not 
been able to do this with black bear because of past diffi- 

32 



culties in aging. We formerly could call a bear a cub, 
possibly a yearling or an adult. "An adult" is a broad 
category. Age of adults is important because of its bearing 
on reproduction, particularly in the case of the female. 
Therefore, we need to have an age and sex structure. 

There is a new technique that now enables us to get within 
one year of a black bear's age. The technique involves 
examination of cross-sections of tooth samples. We pull 
a small premolar, just alongside the large canine in the 
upper jaw, from animals that we trap. Additionally, the 
hunters in the state who are successful in harvesting a 
black bear return to us voluntarily a front portion of 
the lower jaw from which we extract the large canines and 
do a cross-section on that to see the cementum annul i that 
lie within. The principle is almost exactly the same as in- 
volved in tree growth. During the spring and summer, when 
vegetation is lush and nutrition is at its highest, there 
is active depositing of bone and tooth cells. This depositing 
slacks off during the winter months, resulting in alternate 
layers annul i which can be observed and counted under 
the microscope. The first upper premolars lie immediately 
behind the large canines. Dental forceps were used for 
initial premolar extractions, but were discontinued in favor 
of a standard 8-inch screwdriver. Professionally, this may 
sound crude, but it's the best tool we've found yet. The 
matchhead size tooth lies immediately adjacent to the large 
canine. By inserting the blade of the screwdriver between 
the two and twisting, the tiny tooth will roll out of its 
socket with little resulting gum damage. Removal of an 
upper premolar provides good drainage and we have found 
that an oral antiseptic is not necessary. 

This photograph of an unprocessed canine tooth cross-section 
(see Figure 1, page 34) will give you a rough idea of what 
we are looking for. This is just a very rough cross -section , 
polished just a little bit. The area on the extreme left, the 
white band, is the enamel portion of the tooth. The next layer 
containing the cementum layers that we're after. The inner- 
most region is the root canal, which closes in with age. 

The tooth samples are put in a formic acid solution for 
about a week. This de-calcifies or removes all the enamel 
on the tooth leaving it soft and pliable, almost rubbery. 
It is then placed in a paraffin bed and a freezing microtome 
is used to section it to about 5 microns which is then 
mounted on a slide to go through a stain, alcohol and 
washing procedure. You end up with something like this (see 
Figure 2, page 34). This particular photograph is not a photo- 
micrograph, but does show the presence of the annul i . The enamel 
has been removed by the acid. The area on the extreme left 

33 




FIGURE 1. Unprocessed canine tooth cross-section 




FIGURE 2. Processed canine tooth cross-section, annular 
rings visible on the extreme left hand margin 



3 4 



hand margin of this photograph of the tooth section is the 
dentine. Within it you can see the annul i . On this photograph 
you can count most, but not all of the annul i which tend to 
be compacted in older animals. Under the microscope the 
annul i can be separated. This particular animal was a 19-3/4 
year-old male that was killed in Rockbridge County in 1973. 
It was killed on the Game Commission's Goshen-Little North 
Mountain Wildlife Management Area. The oldest specimen 
we've had, a 20-3/4 year-old female, was also obtained from 
one of our hunting areas. She had been tagged originally on 
the Big Levels area of Augusta County in 1958 and was esti- 
mated to be 2-1/2 years-old when captured. Interestingly, 
she was killed within 1/4 mile of the original trapsite. 
The oldest animal that we have trapped to date was a 16-3/4 
year-old male weighing 360 lbs. trapped here in the park in 
1975. It was not the largest animal trapped. Weights of bears 
handled have varied from 8 pounds to a known 580. We've 
had two males exceed our earlier 600-lb. scale capacity. Drug 
dosages indicated weights for these two animals of 705 lbs. 
and 750 lbs. for the 7-1/4 year-old and 10-1/4 year-old 
bears respectively. We have since acquired a friction 
tensiometer with capabilities of + 1% accuracy up to 1,000 
lbs. Unfortunately, we've not been able to recapture either of 
those two animals to document their true weights. 

Following processing, the antagonist for the original drug 
(M50-50 Diprenorphine) is injected directly into the femoral 
artery. The animals are normally "up and running" within 
1-3 minutes. Subcutaneous or intra-muscular injections may 
require 20-45 minutes for recovery. We have a number of 
visitors along occasionally. The recovery phase is always 
a bit dramatic for them. We have a standard "three-minute 
rule" now. If the bear hasn't recovered within three minutes, 
our guest gets to walk up to the bear and shake him with his 
foot! 

One of the first signs of initial recovery is the rapid return 
of the respiration rate to normal "panting." This is followed 
by twitching movements of the ears while the animal lies 
quietly. Once this stage is reached, any sudden noise 
will generally bring them up at a run. We have yet to have 
the first agressive response following recovery from any of 
the nearly 500 animals handled. Their natural reaction is 
to instinctively retreat to the nearest cover available. 

I'd like to introduce some of the data we've compiled thus 
far. For bears trapped and harvested from 1972 to 1974, the 
average age for the harvest sample was 4.2 years for males, 
5.83 years for females and 4.83 years for combined sexes. 
The harvest sample doesn't differ greatly from the trapping 
sample. The average age for the trapping sample was 3.54 

35 



years for males, 6.19 years for females and 4.62 years for 
combined sexes. Female survival appears greater in both 
samples, especially the trapping sample. 

A comparison of age and sex structures of both samples 
indicates certain similarities . Both harvest and trapping 
samples are composed primarily of younger age (1-3 year-old) 
male bears. Females predominate in the older age classes 
in both samples. 

We get a striking contrast when we examine the population 
structure of the bears that have been tagged and subsequently 
harvested, poached or accidently killed by vehicles. No 
females appear in this sample beyond 6 years of age! The 
great majority of these bears were trapped in the park and 
subsequently harvested in close association with the park. 
The data imply that the female segment of the population 
receives a large degree of protection by virtue of the size 
and security of preserved lands. Females appear to be "home 
bodies," occupying a relatively small home range of 1-10 
square miles; whereas males may use from 10-100 square miles. 
The greater range of the male frequently carries him away 
from the protection of the park to areas where he may be 
harvested. 

We examined the proportion of the tagged bears harvested 
annually as a means of estimating the proportion of the total 
population harvested annually. We have tagged 231 bears from 
1972 to 1975. Eighty-four (84) tagged bears are known to 
have been removed from the population to date . (36 . 47,) . 
Fifty-six (56) of the 231 tagged bears were recovered the 
first fall following tagging (avg. 247,). Mortality figures 
are minimum known reported kills. Unreported illegal hunting 
no doubt has removed additional tagged animals from the 
populations . 

In four years , 9 of the 12 animals trapped and tagged in 
1972 are gone from the population (75%). In 1973, we trapped 
and tagged 97 bears in the Shenandoah National Park. Thirty- 
two and nine tenths percent (32.97o) were harvested the first 
year. Not all this was legal. In 1974, an additional 97> 
were removed. An additional 57, was removed in 19 75. The 
total to date removed from the population in a three-year 
period is almost 507,. Average mortality for the three 
trapping periods provide at least two years recovery data 
indicating that 43.97, of the tagged population is gone within 
a two-year period. Since the majority of the tagged bear 
mortality is closely associated with the park, the observed 
mortality should be considered a minimum when applied to 
hunting lands . 

36 



We have added tremendously to our knowledge of the black 
bear in a very short time. In addition to age and sex struc- 
ture data, we are obtaining new knowledge on the handling 
of nuisance bears, movements, home ranges, reproduction 
and mortality. We wish to extend our thanks to the personnel 
of the Shenandoah National Park for their kind assistance 
and for allowing us to use this area for intensive study of 
this fine animal. 



37 



STATUS OF KNOWLEDGE OF THE GEOLOGY 
OF SHENANDOAH NATIONAL PARK 

John C . Reed, Jr .* 



I will talk a little about the status of our knowledge of the 
geology in the park and surrounding regions, but perhaps it 
is appropriate to start with a couple of remarks about 
research in the national parks in general. It seems to me 
that there are three general types of research that go on in 
the parks . 

The first type is research which is directly related in some 
way to the management, regulation, development or interpre- 
tation of a park. For example, the studies of the burns on 
Big Meadows have a bearing on management. Studies of the 
geology related to the location of ground water resources 
for camp-grounds have a bearing on development . 

A second kind undertaken here because the park provides a 
controlled setting necessary for that particular type of 
research, would generally be biological research of one kind 
or another where you need a protected population or a protected 
ecological situation. 

The third type of research is undertaken not because it's 
a park area, but because the park is just part of the general 
area of study. Most geologic studies fall in the latter 
category. Obviously, studies of geology do play a part in the 
interpretive program in a park and in a few cases play a part 
in the management and development plans . But by and large 
in geology we make the studies because the park is part of 
the broader area of interest. 

So let's now take a look at where Shenandoah fits into the 
geology of this part of the country. There are obvious 
differences in the landscape and physiography of the different 

*Chief, Office of Environmental Geology, U.S. Geological 
Survey 

38 



parts of this region: the Blue Ridge, the Great Valley, the 
Valley and Ridge Province, the Appalachian Plateau to the 
west, the Piedmont Plateau and the Atlantic Coastal Plain 
with the great estuaries formed by drowned rivers such as 
Chesapeake Bay. 

Starting with the Blue Ridge, we have a great upfold in the 
core of which are exposed ancient granite gneisses . These are 
flanked by a series of greenstones and sedimentary rocks 
known as the Catoctin Formation which are well described in 
the literature of the park. This whole unit is one great 
upfold, so that the rocks on the west side continue right 
around the nose to appear again on the east side. 

West of the Blue Ridge are the thick sequences of folded 
limestones, shales, and sandstones that underlie the Valley 
and Ridge Province. The layers of sandstone resist erosion and 
stand out to form ridges. The limestone and shale layers 
form the valleys . These long continuous ridges and intervening 
valleys are obvious on a satellite photograph of the region. 

East of the Blue Ridge is the Piedmont Plateau, underlain 
by a complex series of metamorphosed and highly contorted 
rocks that originally were sedimentary and volcanic rocks 
but which are now so highly altered and deformed that their 
original character is difficult to decipher. Chiefly these 
are schists and gneisses but in a few places there are 
downfolds of less metamorphosed rocks, which occasionally 
contain fossils . Some of these fossils are of the same age as 
the fossils contained in some of the unmet amor phosed sedimen- 
tary rocks west of the Blue Ridge. 

East of the Piedmont Plateau is the wide expanse of the 
Atlantic Coastal Plain, underlain by layers of soft sand and 
clay that form a wedge that thickens seaward and actually 
extends hundreds of miles offshore. It is the offshore part 
of this wedge that may contain oil and gas deposits on the 
Atlantic Continental Shelf. 

One other unit that I neglected to point out to you before 
is a series of basins just east of the Blue Ridge and in 
general separating the Blue Ridge from the Piedmont. These 
basins contain sedimentary rocks that are older than those 
of the Coastal Plain, but much younger than those of the 
Valley and Ridge, Blue Ridge, or Piedmont. These are the 
red sandstones and shales that underlie the area between 
Culpeper and Manassas . Locally these rocks contain tracks of 
dinosaurs. The basins characteristically are bounded by faults 
on one side and by an erosional contact on the other. 

This gives you a rough feeling of the variety of geology 

39 



with which we deal and a general idea of where these various 
rock types are found. But what I really was supposed to talk 
about is the status of our knowledge of the geology. I think 
perhaps the most profitable way to do this is to talk about 
the advances in our knowledge over the last fifteen or twenty 
years . 

The general outline of the geologic framework I have described 
was well known by the 1930's. Studies had gone on in the park 
area as early as 1880 and by 1930 we knew the basic outline. 
But in the past forty years, there have been three major 
advances in the knowledge of geology as a whole and the 
eastern United States in particular. 

The first of these advances is the detailed knowledge of 
rock locations and arrangements gained as a result of hard 
work by survey parties and mapping teams . A geologic map 
of Virginia was published in 1958. Since the publication 
of that map, detailed geologic mapping has proceeded to a 
point where the entire area of Shenandoah National Park 
has been mapped at a scale of one inch to a mile . I under- 
stand that this map will be published by the Virginia Division 
of Mineral Resources by mid-summer. At the same time, geologic 
mapping has been going on in a number of other areas: in the 
northern part of the Blue Ridge, in the area between Quantico 
and Fredericksburg, in the Richmond area, and elsewhere in 
the Blue Ridge, Piedmont, and Valley and Ridge. These studies 
have been under the auspices of the Virginia Division of 
Mineral Resources, the U.S. Geological Survey, and a number 
of colleges and universities . 

In conjunction with the geologic mapping we have begun to 
learn a great deal more about the origin of various rock 
types and about the relations of one group of rocks to another. 
For example, during the early mapping the origin of the 
greenstone here in the Blue Ridge was not understood. Since 
that time, it has been well established that the greenstones 
were lavas . We can now talk about what kind of lavas they 
were and under what sort of conditions they were erupted. 
Similarly, sizable bodies of rocks in the Piedmont that were 
previously thought to have been of igneous origin--granites 
of some kind or another--have now been proven to be deposits 
formed by vast chaotic submarine slides, subsequently meta- 
morphosed and uplifted, and now in a state that is difficult 
to distinguish from igneous rocks. Once we understand the 
origin of such rocks we can better comprehend the geologic 
history of the region. 

One of the most difficult problems the early geologists 
faced was trying to discover the relationship between the 
sedimentary rocks west of the Blue Ridge and the metamorphosed 

40 



rocks east of the Blue Ridge--in other words, the relationship 
between the rocks of the Valley and Ridge Province and the 
rocks of the Piedmont Province. The reason this has been so 
difficult to establish is that throughout most of this part 
of the Appalachian Mountains, the Triassic basins separate 
the Blue Ridge and the Piedmont, and there is no way to trace 
one group of rocks into another. But within the last decade, 
the relations have become pretty well established by detailed 
studies of the arrangement of the rocks and the structures 
that they contain. Careful field studies of this kind represent 
one of the major fronts on which geologic knowledge has 
advanced . 

Another major advance in our knowledge, one that is equally 
important, has been the development of ways of determining 
the absolute ages of rocks and minerals. Up until about 1950, 
geologists could generally determine that one rock body was 
older or younger than another nearby body. We could determine 
that one rock stratum containing fossils was older, younger, 
or equivalent in age to another fossilif erous rock stratum 
in some other part of the world by studying the fossils, but 
we had no way of establishing the absolute age of the rocks. 
The techniques of geochronology , or determining absolute 
ages using the decay rates of natural radioactive isotopes, 
have become some of the most powerful geologic tools that 
have evolved in the last few decades. 

Let me describe some of the results of these dating studies. 
The accepted figure for the age of the earth is now in the 
neighborhood of 4.5 billion years. This, incidentally, is 
about the age of the oldest rocks returned from the moon. 
If we take a standard yardstick and let it represent the age 
of the earth, a billion years is equivalent to about eight 
inches. The major geologic eras are the Paleozoic, the Meso- 
zoic, and the Cenozoic. The first well organized fossils on 
which our fossil time scale depends appears about 550 million 
years ago. Thus most of the rocks that we are able to date 
up until the advent of geochronology occupied only the last 
5 inches of the yardstick of geologic time. The time since 
the origin of man represents only about the last l/50th of 
an inch of that yardstick! 

In order to illustrate the vastness of geologic time that 
modern geochronology has established, let me ask you to imagine 
walking backwards in time at the rate of about one step a year. 
It would take you about 115 steps, or slightly less than the 
length of a football field, to get back to the time of the 
Civil War. One and a third football fields would take you to 
the time of the Revolution; and you'd have walked a quarter 
of a mile to get back to the time of Columbus. You'd have 
walked somewhat less than five miles to get back to the 

41 



building of the Pyramids of Egypt and about 1000 miles to 
get back to the time of the first man. To get back to the 
beginning of the Mesozoic Era, the age of the dinosaurs, 
you'd have walked 65,000 miles, or 2% times around the world. 
In order to get back to the age of the earth, you'd have walked 
4% times the distance to the moon. 

When we consider the geology of Shenandoah, we find that the 
granites and gneisses that make up the core of the Blue 
Ridge range in age from about 1 billion years to about 1.1 
billion years . The lavas of the Catoctin Formation now are 
thought to have an age of about 820 million years . This age 
is not precisely determined but it's the best information we 
have at the moment. As we go south in the Blue Ridge, we find 
vast thicknesses of rocks of approximately similar age. The 
Great Smoky Mountains are underlain by tens of thousands of 
feet of sedimentary rock the age of which is believed to 
be about equivalent to the age of the Catoctin lavas here . 

The next younger group of rocks exposed in the park are the 
basal beds of the sequence of sedimentary rocks of the Valley 
and Ridge Province. These are the quartzites and shales of the 
Chilhowee Group, that are found in a few places on the crest 
of the Blue Ridge, but which crop out almost continuously 
along the west foot of the Blue Ridge. They have an age of 
just a little bit more than half a billion years, about 550 
million years . 

The younger sedimentary rocks of the Valley and Ridge Province 
form a continuous sequence that goes upward in age to about 
250 million years . 

Rocks in the Triassic basins east of the Blue Ridge range in 
age from about 180 to 190 million years, and the strata of 
the Atlantic Coastal Plain have an age of about 80 million 
years going up almost to the present. 

Lastly, we find the youngest deposits in the Blue Ridge-- the 
talus slopes in which the salamanders live, and the other 
surficial deposits. 

Even more impressive than the length of time that is repre- 
sented by these rocks is the fact that all rocks preserved in 
this part of the Blue Ridge represent only about 10 percent 
of the time that has elapsed since formation of the earth. 
We must also be aware of the episodes during which the rocks 
were folded, faulted, and metamorphosed to form the Appalachian 
Mountains. These episodes climaxed about 450, 350, and 230 
million years ago. This understanding of the framework of 
geologic time is the second main front on which the knowledge 
of geology has advanced in the last decade or two. 

42 



The third advance has been the development within the last 
fifteen years of the concept of plate tectonics. This has 
had an effect on the earth sciences that is just as funda- 
mental and just as far reaching as the development of the 
theory of evolution was for the biological sciences . 

Until the development of the plate tectonic concept, we were 
pretty much observing isolated facts and describing isolated 
phenomena without any sort of integrating model. Briefly, the 
idea is that the entire crust of the earth is divided into a 
small number of relatively rigid plates that are slowly 
moving with respect to one another. The plates are moving 
away from each other at the mid-ocean ridges such as the Mid- 
Atlantic Ridge and the East Pacific Rise, while the plates 
are converging at the ocean trenches . 

Consider a mid-ocean ridge with crust moving away from it 
on both sides and new crust forming in the middle. The pro- 
cess is rather like two ice floes moving apart and new ice 
forming in the open water between. New crust constantly 
forms in the area of volcanic activity at the crest of the 
ridge, and becomes part of the plates moving away from the 
ridge. What happens when one of these plates meets a plate 
moving away from another ridge? What happens is that one 
of the plates moves down beneath the other one. The down- 
going plate is carried to a depth within the earth's mantle 
where the temperatures are high enough that the plate is 
melted and returned back into the mantle. 

One of the rules of plate tectonics seems to be that the crust 
under the oceans is thinner and denser than the crust under 
the continents . When an oceanic plate meets a continental 
plate, it is the oceanic plate that turns down and is con- 
sumed. This process is described as subduction. Just to 
give you some of the evidence on which the theory of plate 
tectonics is based, we can review a world map showing the 
distribution of earthquake epicenters during a ten year period 
The ocean ridges are marked by a very distinct line of 
earthquake epicenters, but most of the major earthquakes 
occur along the subduction zones where plates are turning 
down and being consumed. The pattern fits beautifully the 
pattern of the plate boundaries . 

Again you ask, what does this have to do with the geology of 
Shenandoah? Well, I should digress just a minute and discuss 
a little bit more of the detail of what is thought to happen 
at one of these converging plate junctions . The oceanic plate 
is colliding with the edge of a continental plate and is 
going down. The continental material is presumably very 
much like that exposed in the granites and gneisses here in 
the Blue Ridge. As the plate goes down, the temperature 

43 



rises because of friction and some of the material at the edge 
of the continental plate and some of it in the down-going 
plate, is melted, moves upward, and erupts as of volcanoes. 
This forms a chain of volcanic islands, much like the Island 
of Japan. Earthquakes are occuring along the down-going plate 
and the chain of volcanoes is forming on the overriding plate 
above it. The rocks between are increasingly deformed and 
belts of folds created. This goes on until another continental 
plate is carried into the subduction zone. Because the continen- 
tal material is lighter and thicker, it can't be subducted 
and when that collision occurs the subduction stops and a 
mountain chain is formed, with folded and faulted volcanic 
and sedimentary strata. 

With the development of the plate tectonic concept, it became 
possible to begin understanding some of the fundemental 
causes for the formation of the Appalachian Mountains . A 
map showing a reassembly of the continents as they were thought 
to have appeared about 180 million years ago would indicate 
the outer edges of mountain systems which are the same age 
and the same structural style as the Appalachian system. 
Mountains similar to the Appalachians in Africa, in Newfound- 
land, in Ireland, Great Britain, Norway and Greenland can all 
be fitted into a coherent picture in which the structures and 
the various rock belts can be reassembled. This mountain 
system, which has been referred to as the Caledonide or 
Appalachian-Caledonide system, is thought to have originated 
from a collision between the African and European plates on 
the east, and the American plate on the west. This collision 
occured during the interval from about 450 million years ago 
to about 250 million years ago. 

At that time, the continents would have been assembled and 
since that time they have been spreading from the Mid-Atlantic 
Ridge, forming new crust until we have a situation today 
wherein the old mountain system fragmented- -some parts (the 
Appalachians) in North America, other parts in Africa, Green- 
land, the British Isles, and Norway. 

This is a very nice model of the evolution of the Appalachian 
Mountain system and the Atlantic Ocean starting from about 180 
million years ago and going forward. But the model can also 
be applied going backward. The granites and gneisses that 
form the core of the Blue Ridge, the billion year old rocks, 
are presumably part of an original crustal plate that included 
all of North America, Europe, and Africa. This plate was 
ruptured about 800 million years ago and during that rupturing 
the lavas of the Catoctin Formation welled up in the rifts 
that were formed as the plate came apart. As spreading 
continued the first Atlantic Ocean was formed. Many of the 
sedimentary rocks which we now see in the Valley and Ridge 

44 



Province were deposited on the submerged edge of the North 
American continent as that early Atlantic opened. They were 
deposited on the trailing edge of the continental plate. 

About 450 million years ago, for some reason, this movement 
reversed and the ancestral Atlantic began to close by sub- 
ducting crust along the eastern edge of the American plate. 
During that interval, a chain of volcanic islands formed. 
Associated sedimentary and volcanic rocks were deposited in 
shallow seas behind the island chain in a setting much like 
the present Sea of Japan. Finally, as subduction continued, 
Africa approached North America and collided with it. The 
rocks of the island arc were crumpled and metamorphosed and 
these are what we now see as the metamorphosed sedimentary 
and volcanic rocks of the Piedmont. 

About 180 million years ago the direction of motion changed 
again. The fissure between the two continents began to open 
once more. As this happened, lavas which were very similar to 
the old Catoctin lavas were erupted. As the continents were 
pulled apart, a series of basins formed that collected debris 
and alluvial materials that now form the sedimentary rocks 
in the Triassic basins. As the new Atlantic continued to 
open, flat-lying sedimentary layers were deposited on the 
submerged trailing edge of the continent. These rocks are 
the strata we now see in the Atlantic Coastal Plain. As you 
see, we have now evolved from a series of isolated observa- 
tions of where rocks are and how they relate to one another 
to a picture that begins to make sense on a global scale, 
both in space and in time. Nobody can say that all details of 
this interpretation are right, but it gives us an integrating 
model which can guide our observations and against which we 
can check some of our conclusions . 

So the three main advances in our knowledge of the geology of 
Shenandoah are: greater knowledge of the regional geology, 
better understanding of geologic time, and a better inte- 
grating model with which to compare our observations . 

In closing, it might be worth suggesting some of the lines 
of geologic research that would be valuable in the future . 
First of all, I think more detailed studies of the origin and 
age of the granitic basement rocks is needed. This would give 
us a clue to the processes and the time of formation of the 
original continental plate. Also needed is further investiga- 
tion of the Catoctin lavas: determining their age more 
exactly, locating the centers from which they were erupted, 
and learning more about the conditions under which eruptions 
occurred. Further studies of the sandstones and shales of 
Chilhowee Group would give us better clues to the direction 
from which the materials came, the rate at which they deposited, 

45 



and the processes that affected them. Another useful group 
of projects would be studies of details of the deformation 
and of the metamorphic history of all of the rocks . These 
studies would give us more insight into exactly what happens 
during the collision of two continental plates--exactly 
when the folds and faults formed, and when rocks were meta- 
morphosed . 

And last, and I think perhaps to me the most promising and 
the most exciting research would be studies of the processes 
by which the landscape is being shaped today--the origin of 
the talus slopes, the origin of the boulder trains, the rela- 
tionship between the biologic community and the geologic 
setting so beautifully illustrated by the discussion of the 
salamanders in another paper. It should be possible to learn 
whether those talus slopes are forming today, whether they're 
moving or stable. All of these are things which should be 
investigated and I'm sure can be. 

Studies of the details of the late Quaternary history of the 
Appalachians will give us insight into the reasons for the 
present distribution of the plant and animal species . These 
studies are at the interface between geology, which goes 
back billions of years, and archeology and history, that go 
back thousands or hundreds of years . 



46 



MONITORING FOREST INSECT OUTBREAKS 
IN THE SHENANDOAH 

Timothy C. Tigner* 



The gypsy moth is expected eventually to become a serious 
pest in Virginia. This insect has aroused great public 
concern in the Northeast, primarily as a severe nuisance in 
residential and recreation areas. Since prolonged and exten- 
sive defoliation has usually occurred on poor sites where 
trees are of low commercial value, timber production has not 
been significantly affected. 

No one knows what impact the gypsy moth will have in Virginia. 
In order to evaluate the effects of such hardwood defoliators , 
the Virginia Division of Forestry has established long-term 
survey plots in areas of suitable forest type where outbreaks 
are likely to occur. With cooperation from personnel of the 
Shenandoah National Park, one series of plots was located 
across Skyline Drive from below Stony Man summit, near Sky- 
land, to a point above Whiteoak Canyon Falls. Trees in these 
plots are examined periodically to assess their condition and 
to monitor changes. Insect populations are evaluated at the 
same time. By determining forest and insect conditions in 
this area prior to gypsy moth establishment, we will be 
able to evaluate the effects of future infestations more 
accurately. 

When survey plots were established in the park during 1974, 
12 percent of the study trees were dead or declining in 
vigor. This reflects the poor site and generally overmature 
condition of the forest. The same year, an insect called the 
fall cankerworm caused heavy defoliation of about 300 acres 
around Skyland. Feeding was less severe in 1975 and is not 
expected to be noticeable in 1976. Any effects of this de- 
foliation should show up within the next few years. Eventually, 
the survey plots can be used to evaluate insect sampling 

' c Entomologist , Insect & Disease Investigation, Virginia 
Division of Forestry 

47 



techniques, population prediction systems, biological control 
efforts, or selected aspects of environmental impact. 

Hardwood defoliating insects seldom cause enough timber loss 
to justify expensive control efforts; but large areas of 
defoliation and large numbers of caterpillars do cause 
considerable public concern for other forest values , and in 
residential or recreation areas these insects can have 
serious economic impact. This makes the Shenandoah National 
Park particularly suitable for long-term evaluation of forest 
insect conditions. Study plots are likely to remain undis- 
turbed for long periods, and data collection can be modified 
when necessary to supply information concerning immediate 
public interests. 

QUESTION : Can you tell us a little bit about Dendroctonus ? 

Well, the southern pine beetle has been in outbreak propor- 
tions for a number of years throughout the southeast and is 
truly an economic pest. It is moving north and can be found 
not far from here. It's a killer. When it gets into a pine 
tree the tree almost always dies. It has affected hundreds 
of acres of valuable forest already. But from my standpoint, 
if forest insects get into the park, their primary importance 
is educational. The trees that are here in the park, including 
hardwoods, are in large part valueless from a commercial 
standpoint. They are overmature, they are growing on poor 
sites, and commercial interest in park lands is minimal. 
There will be pine trees dying; some are dying now in the 
National Forest south of here. These are largely poorly- 
formed trees in out-of-the-way places that couldn't be cut 
if we wanted to. The way market conditions are now, we 
couldn't sell them if we cut them. My own opinion is that the 
sensible thing to do with infestations in the park is to 
study them and try to learn something. We really know very 
little about most forest insect problems because we have been 
overwhelmed by their complexity. 

QUESTION : How many local species of parasites are there 
that might be expected to parasitize the gypsy moth? 

None that we can be sure about. 

QUESTION : Are there any proposals to bring parasites in? 

Yes . That has been a big move by a number of agencies 
including the Virginia Division of Forestry. The problem is 
that we know so little about the organisms involved. We 
don't know much about the gypsy moth; we don't know much 
about the parasites, except which ones they are. A great 
number have been introduced into this country and a number 

48 



have become established. But there is not a satisfactory 
system yet for sampling the gypsy moth. And the only way 
to evaluate the effect of a parasite is to see what effect 
it has on the host, in this case the gypsy moth. To know 
that a parasite causes 98% parasitism of a given stage is 
meaningless. It doesn't mean anything at all unless you know 
what that 98% parasitism does to the host population. Since 
we cannot yet sample the gypsy moth very well, we don't 
know the value of any of the parasites. 

QUESTION : Are these parasites species specific? 

There is a tremendous range. Some of them are monophagous , 
or host specific. Some of them are terribly polyphagous. 
One which is established in Virginia - a parasite introduced 
from Europe - has over 200 known native hosts. We haven't 
recovered any other introduced species in Virginia. There 
is no way of evaluating them if we did. Obviously, we cannot 
establish a parasite unless it attacks insects other than 
gypsy moths, because we don't have the gypsy moth yet. We 
have to introduce parasites that can survive on something 
else. That is not an easy thing to do, and often you never 
know whether you have done it or not. 



49 



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